Pneumatic Focusing Gas Chromatography (PFGC, patent pending) has achieved a limit of detection of 20 parts per trillion (0.8 pmol/liter) for benzene in ambient air in Portland OR. PFGC has a FID for universal hydrocarbon detection. Major endogenous compounds in human breath are methane, methanol, ethanol, acetone, methyl acetate, and isoprene. Their concentrations range from 80 nmol/L for methane to 400 pmol/L or less for methyl acetate. More than 1000 additional compounds have been reported present in human breath, many originating in the inhaled air. Exposure to toxics such as BTEX or other industrial chemicals will evidence itself in breath as well as in the ambient air environment. PFGC can detect the compounds already established in breath and ambient air with better sensitivity and lower cost than current instrumental methods. PFGC has the potential to standardize the methodology of breath analysis research. The goal of Phase I is to modify 3 commercial gas chromatographs for pneumatic focusing and demonstrate their performance in single and dual-column modes. Specific capillary column choice for resolution and selectivity will be evaluated. Performance will be evaluated with simultaneous indoor air/breath analysis for assessment of toxic exposure and uptake through the lungs of volatile organic compounds. PROPOSED COMMERCIAL APPLICATION: Potential commercial applications include breath analysis for exposure assessment onsite, and in standard monitoring profiles, as a research tool of human and other organismal exposure and metabolic studies, and for life insurance screening for passive markers of drug use, tobacco smoking, and as a toxic chemical exposure assessment tool.